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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1011

Závislost na jehle v souvislosti s psychopatologickými charakteristikami a mírou rizikového chování u injekčních uživatelů drog / Needle fixation in relation to psychopatological characteristics and risk behavior of injecting drug users

Čížkovská, Dominika January 2020 (has links)
Background: At the point, when injecting still seems to be the most common use among problem drug users and there has been no change in the long term, despite the long tradition of harm reduction services in the Czech Republic, it is important to examine the context of this issue and try to understand it more closely, and therefore understanding the phenomenon of needle fixation. Aims: The paper seeks to address whether the risky behaviour level of the needle-fixated drug users differs from those who are not needle-fixated. The second aim is to examine a possible connection between the injecting users psychopathological characteristics and the phenomenon of needle fixation. The third intention of the work is to find out whether and pošibly how the level of risky behaviour differs among needle-fixated drug users in the context of their psychopathological characteristics. Methods: The chosen method of data collection was a battery of questionnaires: IN-COME questionnaire, BBV-TRAQ, SCL-90 and NEFPRO. The battery of the questionnaire was administered with the participation of the researcher. In addition to descriptive statistical methods, the Mann-Whitney test (4 tests), the Chi-square test (11 tests) and the Spearman correlation coefficient were chosen as methods for testing based on research...
1012

Význam bakterií pro rozklad dřevní hmoty v lesních ekosystémech / The importance of bacteria for deadwood decomposition in forest ecosystems

Némethová, Ema January 2020 (has links)
Forest ecosystems represent a huge reservoir of carbon. The volume of deadwood in managed forests is in the tens of m3 h-1, while unmanaged forests have the volume of deadwood in hundreds of m3 ha- 1. Deadwood is a substrate with a high potential for decomposition. However, deadwood is a specific habitat that has a high C/N ratio and changes due to ongoing decomposition. The C/N ratio decreases with increasing decay time. In addition to the C/N ratio, the pH also changes during the wood pulping process, due to the decomposition of plant biomass by fungi. Moreover, deadwood has a high impermeability. The main decomposers of dead wood are fungi. In addition to them, bacteria, which are numerous in deadwood, also contribute to decomposition. Bacterial communities that decompose woody biomass are affected by these factors, and their distribution is also affected by dead tree species. The aim of this study was to describe how bacterial communities associated with deadwood change during decay. The most significant factor in the decomposition by bacterial communities is the time of decay. Bacteria found in short-decaying wood (less than 16 years old) are more diverse than those found in long-decaying wood. Methylotrophic bacteria and N-fixing bacteria are common in short-decaying wood as well. N-fixing...
1013

Från tejp till tyg : en studie om hur processer utvecklatsför att tillverka tyg av reflextejp

Anonsen, Fanny, Jansson, Göran January 2020 (has links)
Denna rapport beskriver arbetet med att konstruera utrustning för att strimla, tvinna och fixera en flerskiktsfilm i form av reflextejp med avsikten att tillverka garn av den strimlade tejpen där garnet slutligen stickas och vävs till tyger. Avsikten är inte att utveckla reflexgarn eftersom existerande metoder finns för detta, utan att undersöka om garntillverkning från filmmaterial, eller i en förlängning, andra tvådimensionella material lämpar sig för garnproduktion. Om metoden går att utveckla till kostnadseffektiva, industriella processer kan den exempelvis användas för återvinning av textilier i steget innan konsumentnivå. Överproduktion och tyger med fabrikationsfel inom textilindustrin skulle hypotetiskt kunna strimlas till remsor som tvinnas till relativt grova garner i mekaniska processer. En fördel är att materialblandningar och tillsatta additiv som normaltsett försvårar återvinning inte behöver beaktas. Ett annat tänkbart användningsområde är att råvaror som inte är lämpliga till fibertillverkning kan användas förtextilproduktion. Cellulosabaserat material som används till papperstillverkning där papperet sedan strimlas och tvinnas till garner är ett relativt nytt exempel på garnproduktion från tvådimensionell struktur som just nu är under utveckling. De konstruktioner som tillverkades för strimling, tvinning och fixering fungerade för att producera garner som gick att virka, sticka och väva med. En avgörandefaktor för garnkvaliteten var vilken slags polymer som reflextejpens lim var uppbyggd av. Polyuretan visade sig ge det mest användbara garnet och drygt tvåhundrameter garn av detta material tillverkades under arbetet. De processer och metoder som utvecklats är att betrakta som initiala steg, men är uppskalningsbara till kontinuerliga tillverkningsmetoder i industriell produktion. / This report describes the work of designing equipment for shredding, twisting and heat fixate a multilayer film in the form of reflective tape. The intention is to produce yarn of the shredded and twisted tape, where the yarn is finally knitted and woven into fabrics. The intention is not to develop reflex yarns because existing methods exists for this, but to investigate whether yarn production from film materials, or in an extension, other two-dimensional materials are suitable for yarn production. For example, if the method can be developed into cost-effective industrial processes, it can be used for textile recycling in the pre-consumer stage. Overproduction in the textile industry and fabrics with defects could hypothetically be shredded into strips that are twisted into relatively coarse yarns in mechanical processes. One advantage is that material mixtures and additives which normally make recycling difficult need not be taken into account. Another conceivable area of application is that raw materials which are not suitable for fiber production can be used for textile production. Cellulose-based material used for paper where the paper is shredded and twisted into yarns is a relatively new example of yarn production from a two-dimensional structure that is currently under development. The constructions made for shredding, twisting and heat fixation worked to produce yarns that could be transformed into fabrics. A decisive factor for the yarn quality was the kind of polymer on which the tapes adhesive film was made from. Polyurethane was found to provide the most useful yarn and more than two hundred meters of yarn were made from this material during the work. The processes and methods that have been developed are considered initial steps, but are scalable to continuous manufacturing methods in industrial production.
1014

Analyse von Zahnverletzungen durch intermaxilläre Fixierungssysteme mit IMF-Schrauben im Rahmen der Kieferbruchbehandlung

Shehadeh, Muhammad 27 November 2020 (has links)
Einführung: Zu den Immobilisationsmethoden bei Kieferfrakturen gehören die selbstbohrenden Schrauben (IMF-Schrauben). Diese könnten – wie jeder chirurgische Eingriff – zu Komplikationen führen. Eine dieser Komplikationen ist die Zahnwurzelverletzung. In dieser retrospektiven Studie werden die Patienten, bei denen im Rahmen der Versorgung von Unterkieferfrakturen in der Klinik der MKG-Uniklinik-Dresden im Zeitraum von 2011 bis 2015 IMF-Schrauben eingesetzt wurden, klinisch und radiologisch untersucht. Material und Methoden: Ausgewertet wurden die Patientenunterlagen und Röntgenaufnahmen. Bei der Nachuntersuchung wurden sowohl die subjektiven als auch die objektiven Auffälligkeiten der in Nähe der Schrauben stehenden Zähne erhoben. Der Lockerungsgrad, die Zahnverfärbung, die Perkussionsempfindlichkeit sowie die Vitalität der Zähne wurden geprüft. Bei klinisch behandlungsbedürftigen Befunden wurde eine Röntgendiagnostik durchgeführt und die Behandlung in Zusammenarbeit mit dem Hauszahnarzt veranlasst. Ergebnisse: 157 Patienten (49 Frauen/108 Männer) wurden in die Studie eingeschlossen. 633 Schrauben wurden insgesamt inseriert. Davon hatten 563 einen radiologischen Kontakt mit Zähnen. Von diesen Patienten wurden 34,3 % nachuntersucht. Die Nachbeobachtungszeit betrug von 33,3 Monate im Durchschnitt. Es kam bei 27 Schrauben zu einem radiologischen Wurzeldefekt (4,8 %), wovon sechs Fälle behandlungsbedürftig waren: ein avitaler Zahn, eine Pulpaverkalkung, eine interne Pulparesorption und drei Wurzelfrakturen. Im Rahmen der Behandlung dieser Fälle erfolgten eine Zahnextraktion, eine Wurzelkanalbehandlung und vier Zähne werden durch Hauszahnarzt beobachtet. Schlussfolgerung: Die IMF-Schrauben sind eine zuverlässige Methode zur Okklusionssicherung, die aber zu Zahnwurzelverletzungen führen könnte. Hier empfiehlt sich die klinische und radiologische Nachuntersuchung und die Einleitung einer entsprechenden Therapie falls erforderlich. Es ist wichtig, die Schrauben mit dosierter Kraft zwischen den Eckzähnen und ersten Molaren auf Höhe der mukogingivalen Linie einzubringen, um Zahnwurzel-, Nerv- und Kieferhöhlenverletzungen zu vermeiden.
1015

Evaluation of a novel transcortical pin-sleeve system in a calf model

Vogel, Susan R. 04 1900 (has links)
No description available.
1016

Impacts of Rhizosphere CO₂ on Root Phosphoenolpyruvate Carboxylase Activity, Root Respiration Rate and Rhizodeposition in Populus spp.

Matarese, Dawn Marie 01 January 2010 (has links)
Roots live in and have evolved in a high carbon dioxide (CO₂) environment, yet relatively little research has been conducted on the impacts of soil dissolved inorganic carbon (DIC) on root metabolism. In this thesis, I explore the impacts of root-zone DIC on whole plant biomass accumulation, water use efficiency, and above-ground gas exchange. In addition, I explore the impacts of root-zone DIC on root processes: root PEP-Carboxylase activity, root respiration rate and root exudation of Krebs cycle organic acids. Root-zone DIC did not impact biomass accumulation, leaf gas exchange parameters or water use efficiency under the growth conditions examined. Root-zone DIC did increase root PEP-Carboxylase activity, but decreased root respiration (both CO₂ production and O₂ consumption) and decreased organic acid exudation rates. Increase in measurement CO₂ partial pressure was found to cause an instantaneous decrease in root CO₂ production, and I provide evidence that changes in root metabolism (CO₂ uptake by roots) are part of the cause of this phenomenon. A hypothesized relationship between root respiration rate and Krebs cycle organic acid exudation was not supported by my data. I conclude that root-zone DIC has important impacts on critical functions of root metabolism, and should be considered as an important abiotic factor much in the same way atmospheric CO₂ is for leaves and whole plant biology.
1017

Bakterie asociované s rozkládajícím se dřevem / Bacteria associated with decomposing deadwood

Tláskal, Vojtěch January 2021 (has links)
Deadwood is a hotspot of microbial diversity and its decomposition contributes to carbon and nitrogen cycling in temperate forests. The historically recognized importance of fungi in the decomposition of deadwood has recently been complemented by the description of bacterial functions thanks to the rapid progress of culture-independent methods based on the analysis of nucleic acids. To study different aspects of deadwood decomposition, a temperate mixed forest in Zofinsky prales National Nature Reserve was selected as a site with rich historical forestry data where deadwood decomposition represents an important process in wood turnover. The aim of this thesis is to describe role of bacteria in deadwood decomposition at fine scale resolution with respect to community composition, enzyme transcription, and metabolic potential of dominant species. Effects of deadwood age together with pH and water content on the bacterial community composition proved to be more important than tree species identity. Bacteria showed distinct composition between early and late community in decomposing deadwood. The bacterial community was also under a significant influence of fungal community composition. Despite being in a close contact, bacterial and fungal communities differed significantly between deadwood and the...
1018

The marine biogeochemistry of molybdenum

Tuit, Caroline Beth, 1973- January 2003 (has links)
Thesis (Ph. D.)--Joint Program in Marine Geology and Geophysics (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, and the Woods Hole Oceanographic Institution), 2003. / Includes bibliographical references. / Prevailing wisdom holds that the vertical distribution of molybdenum (Mo) in the open ocean is conservative, despite Mo's important biological role and association with Mn oxides and anoxic sediments. Mo is used in both nitrogenase, the enzyme responsible for N2 fixation, and nitrate reductase, which catalyzes assimilatory and dissimilatory nitrate reduction. Laboratory culture work on two N2 fixing marine cyanobacteria, Trichodesmium and Crocosphaera, and a marine facultative denitrifier, Marinobacter hydrocarbanoclasticus, showed that Mo cell quotas in these organisms were positively correlated with Mo-containing enzyme activity. Mo concentrations in Crocosphaera dropped almost to blank levels when not fixing N2 suggesting daily synthesis and destruction of the entire nitrogenase enzyme and release of Mo. Trichodesmium cultures, however, retained a pool of cellular Mo even when not fixing N2. Colonies of Trichodesmium collected in the field have Mo:C tenfold higher than seen in culture, these Mo:C ratios were reflected in SPM samples from the same region. Fe:C ratios for Trichodesmium were between 12-160 pmol:mol in field and culured samples. The Fe:C ratio of Crocosphaera was established to be 15.8 =/+ 11.3 under N2 fixing conditions. Mo cellular concentrations in cultured organisms were too small to significantly influence dissolved Mo distributions, but may slightly affect Suspended Particulate Matter (SPM) distributions. Mean SPM Mo:C ratios were slightly elevated in regions of N2 fixation and denitrification.. A high precision (=/+ 0.5%) isotope dilution ICP-MS method for measuring Mo was developed to re-evaluate the marine distribution of Mo in the dissolved and particulate phase. / (cont.) Mn oxides were not found to significantly influence either the dissolved or SPM Mo distribution. Dissolved Mo profiles from the Sargasso and Arabian Sea were conservative. However, dissolved Mo profiles from the Eastern Tropical Pacific showed both depletion and enrichment of dissolved Mo possibly associated with interaction of Mo with coastal sediments. Dissolved Mo profiles in several California Borderland Basins showed 1-2 nM Mo depletions below sill depth. A more focused study of water column response to sediment fluxes using the high precision Mo analyses is necessary to determine whether these phenomena are related. / by Caroline Beth Tuit. / Ph.D.
1019

Mechanická studie interakce páteřního segmentu s poddajným fixátorem / Biomechanical Study of Interaction between Spinal Segment and Malleable Fixation Device

Manek, Filip January 2014 (has links)
This doctoral thesis is focused on comparative stress strain analysis of a spinal segment with a malleable fixation device and a physiologic spinal segment. In its opening a research study from available sources is carried out. It covers the contemporary state of scientific studies in the given area, anatomy of individual components of the spine, material properties, ways and magnitudes of loadings and also the most common FE model used in similar problems solved. To create a model of geometry of a spinal segment CT scans of a spinal segment of a 38-year-old woman are used. Then they are subsequently used in the modeling software SolidWorks to create the model of geometry of two lumbar vertebras L4 - L5 and a malleable fixation device. Using the computational system ANSYS Workbench, the complete computational model of the spinal motional segment with a malleable fixation device is compiled, covering models of material, loading and bonds. On the basis of the computational solution of FEM models for different ways of loading, a stress-strain analysis is performed. To compare obtained results a detailed comparative analysis with the physiological spinal segment, the segment with the degenerated disc and the segment with applied "rigid" fixation device is carried out. Within the stress strain analysis of the spinal segment with malleable fixation device, an analysis of the magnitude of the strain intensity of spongious bone tissue around the implanted transpedicular screw, depending on the cord pretension of the malleable fixation device, is performed.
1020

Does nutrient availability mediate the temperature dependence of gross primary production?: An evaluation using side-stream experimental channels.

Collis, Lyndsie Michele January 2018 (has links)
No description available.

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